Anti-Ice/Rain Flashcards
(30 cards)
what methods are there for ice + rain protection
- thermal anti-icing
- electrical anti-icing
- windshield wipers
what anti-icing + rain protections are there
- flight deck window heating
- windshield wipers
- probe and sensor heat
- engine anti-ice
- wing anti-ice
window and anti-icing structure (up to 899)
window structure:
- 1+2 = 2 glass panes laminated either side of vinyl core
- 3 = 2 acrylic panes separated by air
anti-icing structure:
- 1+2 = conductive coating outer ply for electrical heating prevent ice build up and defogging
- 3 = not electrically heated
window and anti-icing structure (900 and beyond)
window structure:
- 1 to 3 = 2 glass panes laminated either side of vinyl core
anti-icing structure:
- 1 to 2 = conductive coating on outer ply for electrical heating to prevent ice build up and defogging
- 3 = conductive coating on inner ply for electrical heating to prevent defogging
flight deck window heat operation (up to 899)
- FWD WINDOW HEAT = heating for window 1
- SIDE WINDOW HEAT = heating for window 2
- temperature controllers maintain windows 1 + 2 at the correct temperature to ensure maximum strnegth of the windows in the event of bird impact
- heat is automatically removed in case of window overheat
flight deck window heat operation (900 and beyond)
- FWD WINDOW HEAT = heating for window 1
- SIDE WINDOW HEAT = heating for window 2 + 3
- temperature controllers maintain windows 1 + 2 at the correct temperature to ensure maximum strength of the windows in the event of bird impact
- heat is automatically removed in case of window overheat
- thermal switches for window 3 maintain the temperature correctly
what are the rain removal methods for the forward windshields
- windshield wipers
- permanent rain repellant coating on the windows
which probes and sensors are electrically heated
- pitot
- alpha
- TAT
(static ports are not heated)
on standby power which is probe is still heated
CAPT PITOT (however, the CAPT PITOT light does not illuminate for a failure)
what part of the engine is anti-iced during engine anti-icing operation
engine cowl lip
how does switching the engine anti-icing switch to ON affect the aircraft systems (anti-ice and other)
- cowl anti-ice valve opens
- sets stall warning logic for icing conditions
- adjust stick shaker and minimum maneuver speed bars on the ASI (FMC VREF not adjusted)
- stall warning logic returns to normal when engine anti-ice is positioned OFF if wing anti-ice has not been used in flight
what happens if the cowl anti-ice valve fails to move to the position as indicated by the switch
- COWL VALVE OPEN light remains illuminated bright blue
- amber TAI indication illuminates on the CDS after a short delay
why does the amber COWL ANTI-ICE light illuminate
due to excessive pressure in the duct leading from the cowl anti-ice valve to the cowl lip
what part of the wing is anti-iced during wing anti-ice operation
3 inboard leading edge slats
how does switching the wing anti-ice switch to ON affect the aircraft systems on ground (anti-ice and other)
- opens both wing anti-ice control valves if:
- thrust on both engines is below the setting for takeoff warning activation; AND
- temperature inside both wing distribution ducts is less than the thermal switch activation temperature
- closes if either of the above conditions no longer present (thrust high OR temp high)
- wing anti-ice switch remains in the ON position regardless of the valve position but will trip off automatically at liftoff
how does switching the wing anti-ice switch to ON affect the aircraft systems in flight (anti-ice and other)
- opens both wing anti-ice control valves
- sets stall warning logic for icing conditions:
- stall warning logic adjust stick shaker, minimum maneuver speed bars on ASI (FMC VREF not adjusted)
- stall warning logic remains set for icing conditions for the remainder of the flight, regardless of subsequent wing anti-ice switch position
- duct temperature and thrust setting logic are disabled and have no effect on control valve operation in flight
- valve position is monitored by VALVE OPEN light
window ‘OVERHEAT’ light
- illuminated
- overheat condition is detected
- electrical power is interrupted
window heat ‘ON’ light
- illuminated
- extinguished
illuminated:
- window heat is being applied to selected window
extinguished:
- switch is off
- overheat is detected
- system failure
- system is at correct temperature
‘WINDOW HEAT’ sw
- ON = window heat is applied to selected window
- OFF = window heat not in use
‘WINDOW HEAT’ test sw
- OVHT
- PWR TEST
OVHT:
- simulated an overheat condition
PWR TEST:
- provides a confidence test
‘WINDSHIELD AIR’ knob
-provides air for no. 1 window defogging
windshield wiper selectors
- PARK = turns off wiper motors and stows wiper blades
- INT = 7 second intermittent operation
- LOW = low speed operation
- HIGH = high speed operation
probe heat lights:
- illuminated
related probe is not heated
(if operating on standby power, probe heat lights do not indicate system status)
probe heat switches
- ON
- AUTO
ON:
- power is supplied to heat related system
AUTO:
- power is automatically supplied to both A and B probe heat systems when either engine is running
